FIG. 7 is a cross-section diagram of an existing image reading apparatus. In the figure, 1 is a light source for emitting light; 2 is a lens; 3 is a photosensitive part (photosensitive integrated circuits) for receiving light converged by lens 2; 4 is a sensor substrate for carrying the photosensitive integrated circuits 3 arranged in a straight line; 6 is a framework for accommodating the light source 1, the lens 2 and the sensor substrate 4; 5 is a light-transmitting plate for carrying an original, which is set on framework 6; and 10 is an original.
In the above image reading apparatus, light emitted from the light source 1 transmits through the light-transmitting plate 5, and is irradiated onto the original 10 outside. On the black area of text on the original 10, light is absorbed, and on other areas of white background for the original, almost 100% of the light is reflected. Then the reflected light passes through the glass plate 5, is collected by the lens 2, and is irradiated onto the photosensitive part 3 on the sensor substrate 4. The photosensitive part 3 is composed of many photosensitive pixels, and a driving circuit capable of photoelectrically converting light irradiated onto each photosensitive pixel and outputting signals. The received light, after being converted into electrical signals, is output outward via the driving circuit as image (text) information. The original is moved uninterruptedly, and thus the image (text) information recorded thereon is read out continuously.
There are the following problems in regard to the above image reading apparatus. When the reflected light information of the original is required to be read, both of the light source and the photosensitive part need to be configured to be in a state suited to read the reflected light. Thus at this time, information of exciting light in the original cannot be read. When information of exciting light is required to be read, the light source and the photosensitive part need to be configured to be in a state suited to read the exciting light. Thus at this time, the reflected light information cannot be read. When both reflected light information and exciting light information are required to be read and recognized, a plurality of different types of sensors need to be used. In result, the cost and volume of the image reading apparatus increase, and the subsequent processing section of data thereof is quite complex. These have a strong impact on the application field of the image sensor, and limit the development of the product.